Andy Peters
Well-known member
PRR said:
OK, so it's a simple matter of rewiring the sockets and installing the 6550s?
It's not like I can actually use the amp at home.
Ampeg VT-40 overhaul questions
- Thread starter Matt C
- Start date
Help Support GroupDIY Audio Forum:
OK, so it's a simple matter of rewiring the sockets and installing the 6550s?
It's not like I can actually use the amp at home.
cabcobbler
New member
- Joined
- Feb 11, 2015
- Messages
- 1
I'm new and glad this is here.
I have a 76-79 vt-40- version 2 white rocker switches- with channel one not passing signal, no power to v1.
I ordered the recap kit from fliptops and have done a visual inside chassis. Someone has done some diddling.
The mallory FP288 multi cap- which is 40uf/40uf/500V has the center lugs soldered together leading to a 3.3k ohm 10W cement resistor(with a visible crack) to a turret strip with two 47uf 450V caps. Please see attachment- notice black tape...
The rub- I am on a secluded island where there are no techs I am willing to risk with but have been doing my own repairs to several solid state amps with safety foremost the past several years. This is different I know but I am confident replacing part for part which is what I am planning to do.
What is this mess?
I have a 76-79 vt-40- version 2 white rocker switches- with channel one not passing signal, no power to v1.
I ordered the recap kit from fliptops and have done a visual inside chassis. Someone has done some diddling.
The mallory FP288 multi cap- which is 40uf/40uf/500V has the center lugs soldered together leading to a 3.3k ohm 10W cement resistor(with a visible crack) to a turret strip with two 47uf 450V caps. Please see attachment- notice black tape...
The rub- I am on a secluded island where there are no techs I am willing to risk with but have been doing my own repairs to several solid state amps with safety foremost the past several years. This is different I know but I am confident replacing part for part which is what I am planning to do.
What is this mess?
Attachments
Matt C
Well-known member
safety first, make sure you're comfortable draining all the big filter caps.
since your issue is only with channel 1 that narrows things down a lot. I'd just use a multimeter to search for the B+ voltage that's missing from V1. maybe your amp is a different version than the schematic I'm looking at, but the B+ voltage for V1 comes from the same spot as V2's B+, so if V2 is getting proper voltage supplied to it, my first guess would be an open plate resistor or damaged PCB trace around V1.
since your issue is only with channel 1 that narrows things down a lot. I'd just use a multimeter to search for the B+ voltage that's missing from V1. maybe your amp is a different version than the schematic I'm looking at, but the B+ voltage for V1 comes from the same spot as V2's B+, so if V2 is getting proper voltage supplied to it, my first guess would be an open plate resistor or damaged PCB trace around V1.
